Green Bean Casserole with Real Mushroom Sauce and Crispy Shallots
A casserole built on a silky mushroom velouté instead of canned soup, topped with shallots fried until they shatter between your teeth
The secret to a proper green bean casserole is understanding what a cream soup actually is: mushrooms cooked down until they release their liquid, then thickened with butter and flour into something glossy and deep. When you build your own base, you taste the earthiness of the mushrooms instead of salt and cellulose. The casserole comes together quickly after that—just toss your blanched green beans with the sauce, transfer to a baking dish, and let the oven warm everything through while you fry the shallots. Those shallots are the textural anchor, layers of thin-sliced allium that go golden and brittle in hot oil. They should be done just before the casserole comes out of the oven so they stay crisp when you scatter them over the top.
Green Bean Casserole with Real Mushroom Sauce and Crispy Shallots
Serves 6 · Prep 25 · Cook 35
-
Bring a large pot of salted water to a boil and blanch the green beans for 4 minutes until they turn bright green but still snap when bent—they should be barely tender since they’ll cook more in the oven
-
Drain and spread the beans on a kitchen towel to dry while you make the sauce
-
In a large skillet over medium-high heat, melt 1.5 tablespoons of the butter and sauté the sliced mushrooms, stirring often, until they release their liquid and turn golden brown at the edges (about 6 minutes)
-
Add the minced onion and cook for 2 more minutes until softened and fragrant
-
Stir in the garlic and cook for 30 seconds, then sprinkle the flour over everything and stir constantly for 1 minute so the raw flour taste disappears
-
Pour in the stock and cream, stirring to break up any lumps, and simmer for 5 minutes until the sauce coats the back of a spoon
-
Season with salt and pepper, then toss the blanched green beans into the sauce and stir gently to coat
-
Transfer the mixture to a 9-by-13-inch baking dish and place in a 350-degree oven for 20 minutes until bubbling around the edges
-
While the casserole bakes, heat the neutral oil in a small saucepan to 325 degrees (a shallot ring should sizzle immediately when dropped in)
-
Working in batches so you don’t crowd the pan, fry the shallot rings for 2 to 3 minutes, stirring gently with a slotted spoon, until they turn deep golden and crisp—they should sound papery when you crush one with a wooden spoon
-
Transfer to a paper towel to drain and cool
-
Remove the casserole from the oven and scatter the fried shallots over the surface just before serving
